Página 21 dos resultados de 885602 itens digitais encontrados em 0.221 segundos

‣ Designing interventions that include delayed reinforcement: implications of recent laboratory research.

Stromer, R; McComas, J J; Rehfeldt, R A
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em //2000 Português
Relevância na Pesquisa
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The search for robust and durable interventions in everyday situations typically involves the use of delayed reinforcers, sometimes delivered well after a target behavior occurs. Integrating the findings from laboratory research on delayed reinforcement can contribute to the design and analysis of those applied interventions. As illustrations, we examine articles from the Journal of the Experimental Analysis of Behavior that analyzed delayed reinforcement with respect to response allocation (A. M. Williams & Lattal, 1999), stimulus chaining (B. A. Williams, 1999), and self-control (Jackson & Hackenberg, 1996). These studies help to clarify the conditions under which delayed reinforcement (a) exercises control of behavior, (b) entails conditioned reinforcement, and (c) displaces the effects of immediate reinforcement. The research has applied implications, including the development of positive social behavior and teaching people to make adaptive choices. DESCRIPTORS: delayed reinforcement, response allocation, stimulus chains, self-control, integration of basic and applied research

‣ Temporal discounting: basic research and the analysis of socially important behavior.

Critchfield, T S; Kollins, S H
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em //2001 Português
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Recent basic research on human temporal discounting is reviewed to illustrate procedures, summarize key findings, and draw parallels with both nonhuman animal research and conceptual writings on self-control. Lessons derived from this research are then applied to the challenge of analyzing socially important behaviors such as drug abuse, eating and exercise, and impulsiveness associated with attention deficit hyperactivity disorder. Attending to the broader temporal context in which behavior occurs may aid in the analysis of socially important behavior. Applying this perspective to the study of behavior in natural environments also highlights the importance of combining methodological flexibility with conceptual rigor to promote the extension of applied behavior analysis to a broader array of socially important behaviors.

‣ Reinforcement contingencies and social reinforcement: some reciprocal relations between basic and applied research.

Vollmer, T R; Hackenberg, T D
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em //2001 Português
Relevância na Pesquisa
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Reinforcement contingencies and social reinforcement are ubiquitous phenomena in applied behavior analysis. This discussion paper is divided into two sections. In the first section, reinforcement contingencies are discussed in terms of the necessary and sufficient conditions for reinforcement effects. Response-stimulus dependencies, conditional probabilities, and contiguity are discussed as possible mechanisms of, and arrangements for, reinforcement effects. In the second section, social reinforcement is discussed in terms of its functional subtypes and reinforcement context effects. Two underlying themes run throughout the discussion: (a) Applied research would benefit from a greater understanding of existing basic research, and (b) basic research could be designed to specifically address some of the issues about reinforcement that are central to effective application.

‣ Current and future NIH support of biomedical research.

Lenfant, C
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /07/1997 Português
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Current and future prospects for biomedical research are discussed by examining two critical questions, namely, how much money will be available and how it will be spent. Context is provided first by comparing how those same questions were answered 25 years ago with what has actually occurred between 1972 and the present. The questions are then addressed for a comparable period in the future. Projections are made for future funding for the National Institutes of Health (NIH) and examples of new research directions are described. Ample grounds are provided for optimism about the future of biomedical research and NIH funding for it.

‣ Ethical and research dilemmas arising from a questionnaire study of psychological morbidity among general practice managers.

Sheikh, A; Hurwitz, B; Parker, M
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /01/2001 Português
Relevância na Pesquisa
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A questionnaire-based research project enquiring into the psychological health of general practice managers found that 5% of managers admitted to suicidal ideas. This paper explores the moral issues raised when research conducted at a distance uncovers information about participants which indicates that they may be at increased risk of harm. It examines whether the authors of such studies have responsibilities towards their research participants beyond those of analysing and properly interpreting the data supplied to them. The paper is an exercise in self-reflection and self-criticism; not all the questions posed and explored by it can be answered definitively. Implications for planning studies of this kind are discussed.

‣ Diabetes research: are we getting anywhere?

Zinman, B
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em 01/11/1996 Português
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Although 75 years have elapsed since the discovery of insulin, diabetes mellitus continues to be a chronic disease associated with significant morbidity and mortality. However, progress in basic and clinical research has advanced our understanding of the pathophysiology of the disease. The development of animal models has facilitated research into the autoimmune processes that underlie insulin-dependent diabetes, although the factors that trigger these mechanisms still remain a mystery. Research into non-insulin-dependent diabetes has furthered our understanding of the action of insulin at the molecular and cellular level and raised questions about the genetic basis of the disease. In addition, concerted efforts are being made to improve insulin therapy and develop interventions to prevent or mitigate the complications of diabetes. Researchers are now on the threshold of testing new therapies that one day may change the long-term outcome for people with diabetes.

‣ The breast cancer research scandal: addressing the issues.

Weijer, C
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em 15/04/1995 Português
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The three claims put forward by Dr. Roger Poisson to rationalize his enrollment of ineligible subjects in clinical trials do not justify research fraud. None the less, certain lessons for the conduct of clinical research can be learned from the affair: experimental therapies should be made available to technically ineligible subjects when no effective therapy exists for their disease; further research must investigate the possible benefits of clinical-trial participation; broadly based, pragmatic trials must be regarded as the ideal model; and each eligibility criterion in a clinical-trial protocol should be justified.

‣ Create culture of integrity to defeat research fraud, funding agencies say.

Lowry, F
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em 01/05/1995 Português
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Widely reported cases of research fraud have eroded public confidence in scientific research. When funding agencies met last fall they underscored the importance of integrity in the research process and discussed steps that could be taken to promote it.

‣ New directions in research: report from the 10th International Conference on AIDS.

Berger, P B
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em 15/06/1995 Português
Relevância na Pesquisa
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Research findings presented at the 10th International Conference on AIDS, held in Yokohama, Japan, in August 1994, indicate that few advances have been made in standard antiretroviral therapy for HIV infection. The perinatal administration of AZT (zidovudine) was reported to reduce transmission of HIV from mother to child, and its use in combination with acyclovir appears to improve survival among patients with advanced disease. Other research has focused on asymptomatic patients with long-standing HIV infection. Their survival may be related to the activity of cell antiviral factor, a cytokine produced by CD8+ cells. In gene therapy research, one approach involved the genetic alteration of target cells to enable them to render the virus harmless. A second approach consisted of enhancing the function of CD8+ cells to allow them to compensate for dysfunctional CD4+ cells. The author believes that gene therapy may offer the greatest hope of an effective treatment for HIV infection.

‣ A national committee for the ethics of research.

Gelder, M G
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /09/1990 Português
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A National Committee for the Ethics of Research could consider new questions arising from innovations in research or practice, deal with multi-centre trials, adjudicate when separate local committees give conflicting advice about similar projects, or oversee the work of district committees. The value of each of these functions is assessed and it is concluded that a national committee would be most valuable in providing detailed evaluations of difficult or controversial issues. Though it could offer useful advice about multi-centre trials, local committees would probably wish to continue to consider research involving patients within their health districts even though approval had been given by a central committee. A national committee could usefully oversee the working of a system of quality control throughout the country, but the detailed monitoring of district committees would be done more effectively at regional level.

‣ Minimal breaches of confidentiality in health care research: a Canadian perspective.

Emson, H E
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /09/1994 Português
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In a large proportion of health care research based on the retrospective review of records, minimal breach of patient confidentiality appears to be inevitable. This occurs at initial identification of and access to the chart, selected on the basis of the condition under investigation, and while individual identifiability can be blocked at subsequent stages, at this point it does occur. Prospective individual consent is impractical because often neither the desirability nor the specific subject of the research is known at the time of making the record, and retrospective patient tracing to obtain it is often impossible. I argue that the benefit of the research outweighs the minimal breach of confidentiality, and that in my own jurisdiction, this appears to be envisaged and accepted in Canadian law.

‣ Research on the human genome and patentability--the ethical consequences.

Pompidou, A
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /04/1995 Português
Relevância na Pesquisa
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The genome is one of the primordial elements of the human being and is responsible for human identity and its transmission to descendants. The gene as such ought not be appropriated or owned by man. However, any sufficiently complete description of a gene should be capable of being protected as intellectual property. Furthermore, all utilisations of a gene or its elements that permit development of processes or new products should be patentable. Ethics, in the sense of moral action, should come into play from the very first stages of research into the human genome. Protection of intellectual and industrial property is of purely legal concern and need not provoke ethical consideration. By contrast, the use of the results of, and in particular the commercialisation of products deriving from, research into the human genome, ought to be subjected to ethical consideration and control. Considering the economic and societal stakes of such research, ethical analysis ought to be at an international level if mistakes and unforeseen risks of conflict are to be avoided.

‣ Aftercare for participants in clinical research: ethical considerations in an asthma drug trial.

Harth, S C; Thong, Y H
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /08/1995 Português
Relevância na Pesquisa
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The issue of aftercare for participants in clinical research was explored in the context of an asthma drug trial. Although there may be financial constraints and practical difficulties with implementation, the results show that it may be feasible for clinical investigators and commercial sponsors to take on some limited responsibility for the medical care of research subjects after clinical trials. However, the ethical implications for this practice remain unclear. On the one hand, society may have a moral obligation to compensate and reward some of its members who assume the risk of research subjects for the benefit of society as a whole. On the other hand, the promise of aftercare may provide an inducement to volunteers which, under certain conditions may be considered morally wrong and scientifically unsound.

‣ Research ethics committee audit: differences between committees.

Redshaw, M E; Harris, A; Baum, J D
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /04/1996 Português
Relevância na Pesquisa
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The same research proposal was submitted to 24 district health authority (DHA) research ethics committees in different parts of the country. The objective was to obtain permission for a multi-centre research project. The study of neonatal care in different types of unit (regional, subregional and district), required that four health authorities were approached in each of six widely separated health regions in England. Data were collected and compared concerning aspects of processing, including application forms, information required, timing and decision-making. The key finding was that ethics committees received and processed the applications variably, reflecting individual factors and local problems. To improve consensus and facilitate multicentre studies, standard forms and instructions are suggested and the establishment of a national committee or advisory group advocated.

‣ The role of futility judgments in improperly limiting the scope of clinical research.

Harper, W
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /10/1998 Português
Relevância na Pesquisa
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In medical research, the gathering and presenting of data can be limited in accordance with the futility judgments of the researchers. In that case, research results falling below the threshold of what the researchers deem beneficial would not to be reported in detail. As a result, the reported information would tend to be useful only to those who share the valuational assumptions of the researchers. Should this practice become entrenched, it would reduce public confidence in the medical establishment, aggravate factionalism within the research community, and unduly influence treatment decisions. I suggest alternative frameworks for measuring survival outcomes.

‣ For debate . . . medical research output 1973-81: a romp around the United Kingdom research centres.

Wakeford, R; Adams, R
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em 28/01/1984 Português
Relevância na Pesquisa
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In order to measure output of medical research in the United Kingdom, the computerised database of Excerpta Medica was used to count the number of publications emanating from each centre of research based on a medical school in 1973-81. Data were amalgamated for the first four years (1973-6) and the final four years (1978-81) and the two sets of data were compared. Eight centres showed a substantial change (20% or more) between the first and second periods. In London three medical schools showed an increase in output and one showed a decrease in output. Elsewhere Leicester, Nottingham, and Southampton schools showed an increase and Bristol showed a decrease. The overall contribution of Cambridge did not increase over the decade but the proportion of clinical papers among those produced at Cambridge did increase. There are deficiencies in this type of exercise as all articles are treated equally, but probably some of these problems could be overcome in a more sophisticated analysis. Some measure of weighting of the importance of each paper needs to be devised.

‣ Research ethical committees in Scotland.

Thompson, I E; French, K; Melia, K M; Boyd, K M; Templeton, A A; Potter, B
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em 28/02/1981 Português
Relevância na Pesquisa
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A questionnaire was sent to 41 ethical committees in Scotland requesting information about their constitution and supervision of clinical research. Thirty-four (83%) replies were received. Committees varied in size from one to 73 members, most of whom were medical. Ten had no nurse members and only three had lay members without direct NHS connections. Sixteen saw their role as advisory rather than supervisory. Thirteen had not met in the past year whereas two had held 10 or more meetings. Limited use (12) was made of standard protocols, and only six had formal procedures for monitoring research in progress. Only seven of 370 proposals were rejected outright. Risk/benefit dilemmas and difficulties relating to informed consent were the commonest problems encountered. The committees provide only limited safeguards for patients and research workers, and more effective, standardised procedures are indicated.

‣ The right answer for the wrong question: consequences of type III error for public health research.

Schwartz, S; Carpenter, K M
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /08/1999 Português
Relevância na Pesquisa
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OBJECTIVES: This study examined the impact of assessing the causes of interindividual variation within a population when the research question of interest is about causes of differences between populations or time periods. This discrepancy between the research focus and the research question is referred to as a type III error, one that provides the right answer for the wrong question. METHODS: Homelessness, obesity, and infant mortality were used to illustrate different consequences of type III errors. These different consequences depend on the relationships between the causes of within- and between-group variation. CONCLUSIONS: The causes of inter-individual variation and the causes of variation between populations and time periods may be distinct. The problem of examining invariant causes deserves attention.

‣ White, European, Western, Caucasian, or what? Inappropriate labeling in research on race, ethnicity, and health.

Bhopal, R; Donaldson, L
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /09/1998 Português
Relevância na Pesquisa
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The request for scientifically appropriate terminology in research on race, ethnicity, and health has largely bypassed the term White. This and other words, such as Caucasian, are embedded in clinical and epidemiological discourse, yet they are rarely defined. This commentary analyzes the issue from the perspective of the epidemiology of the health of minority ethnic and racial groups in Europe and the United States. Minority groups are usually compared with populations described as White, Caucasian, European, Europid, Western, Occidental, indigenous, native, and majority. Such populations are heterogeneous, the labels nonspecific, and the comparisons misleading. Terminology that reflects the research purpose-for examples, reference, control, or comparison--is better (unlike White, these terms imply no norm, allowing neither writers nor readers to make stereotyped assumptions about the comparison populations. This paper widens the debate on nomenclature for racial and ethnic groups. Many issues need exploration, including whether there is a shared understanding among the international research community of the terms discussed.

‣ Elevated incidence of childhood leukemia in Woburn, Massachusetts: NIEHS Superfund Basic Research Program searches for causes.

Durant, J L; Chen, J; Hemond, H F; Thilly, W G
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /09/1995 Português
Relevância na Pesquisa
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Between 1966 and 1986, the childhood leukemia rate in Woburn, Massachusetts, was 4-fold higher than the national average. A multidisciplinary research team from MIT, which is being supported by the NIEHS Superfund Basic Research Program, has explored the possible importance of a temporal correlation between the period of elevated leukemia and a previously unrecognized mobilization of toxic metals from a waste disposal site in north Woburn. Residents of Woburn may have been exposed to arsenic (70 micrograms/l) and chromium (240 micrograms/l) at levels in excess of federal drinking water standards (50 micrograms/l for each metal) by consuming municipal groundwater contaminated with these metals. Research is currently underway a) to elucidate the mechanisms and the pathways by which these metals were transported from the waste disposal site to the drinking water supply; b) to determine the identity of the principal human cell mutagens in samples of aquifer materials collected from the site of the municipal supply wells; and c) to measure the extent of exposure and genetic change in residents who consumed the contaminated well water.